1. Field of the Invention
The present invention relates, in general to vehicle window wiper systems, and more specifically, to nozzles for spraying washer fluid onto vehicle windows.
2. Description of the Art
In motor vehicles, the window wipers are typically combined with a window washer system for cleaning the vehicle windshield and/or the vehicle backlight. The washer system typically includes a fluid reservoir mounted in the vehicle from which washer fluid is pumped through a fluid conduit to a nozzle which may be mounted on the vehicle cowl disposed between the vehicle hood and the windshield or on the vehicle hood. In the case of a rear backlight, the nozzle is typically mounted below the rear backlight on the rear door panel or on the rear edge of the roof structure above the rear backlight.
In the case of a cowl mounted nozzle, a stem with a through bore has a pair of resilient latch arms which engage the cowl to mount the stem through an aperture in the cowl. One end of the stem is provided with a barb for attachment to the fluid conduit extending from the washer fluid reservoir in the vehicle.
In a typical configuration, the other end of the stem is mountable in a recess in a detachable nozzle head containing a pair of discharge outlets for discharging washer fluid from the nozzle onto the adjacent vehicle window. The second end of the stem is sealingly attached to the head by sonic welding, spin welding or solvent bonding.
However, the sonic or spin welded bonds do not always prove reliable over long term use thereby resulting in a leak forming in the washer fluid delivery system. In addition, the engagement of the latch arms on the stem with the vehicle cowl places all of the mounting strain on the sonic or spin welded joint between the stem and the head. This strain frequently breaksdown during long term use which adversely effects the reliability of the washer nozzle.
It is also known in washer nozzles to provide a spring biased check valve or ball in an interior bore within the nozzle stem. In one construction, a tapered spring provides the biasing force for the ball, with pressurized washer fluid from the reservoir being sufficient to move the ball away from a ball seat within the stem to allow washer fluid to flow around the ball and through the coils of the spring to the discharge outlet(s)in the nozzle head. This has the potential disadvantage that, under high pressure, the spring could be totally compressed thereby blocking fluid flow to the nozzle head.
Thus, it would be desirable to provide a window washer fluid nozzle which overcomes the problems associated with previous washer fluid nozzle designs. It would also be desirable to provide a washer fluid nozzle which has increased, long term reliable use by use of a unique sealed connection between the stem and head of the nozzle which minimizes the occurrence of leaks between the stem and head of the nozzle.